About 250 million years ago, massive volcanic eruptions triggered catastrophic climate changes that killed 80 to 90 percent of species on Earth. The Permian-Triassic mass extinction, or the “Great Dying,” paved the way for dinosaurs to dominate Earth, but was even worse than the Cretaceous–Paleogene extinction that wiped out the dinosaurs 65 million years ago. Now, with a new fossil discovery described May 22 in the journal Current Biology, scientists believe that a tiger-sized, saber-toothed creature called Inostrancevia migrated 7,000 miles across Pangea. When it arrived in the southern part of Pangea, Inostrancevia filled a gap in an ecosystem that was devoid of top predators before Inostrancevia too went extinct, as Earth’s species fought to gain a foothold on a changing planet. 

[Related: UV radiation might be behind the planet’s biggest mass extinction.]

Inostrancevia was a gorgonopsian and a saber-toothed predator. It was about the size of a tiger and likely had tough skin similar to a rhinoceros or elephant and looked more like a reptile than most mammals alive today.

“It is equally closely related to all living mammals. Inostrancevia and other gorgonopsians have no direct living descendants. The group went completely extinct in the Permian-Triassic extinction, but distant proto-mammal relatives of gorgonopsians called cynodonts survived the extinction and evolved into mammals in the Triassic Period,” study co-author Christian Kammerer told PopSci. Kammerer is the research curator in Paleontology at the North Carolina Museum of Natural Sciences and research associate at the Field Museum in Chicago.

Previously, scientists had only found Inostrancevia fossils in Russia, but the fossils in this study were found almost 7,000 miles away. A team of researchers led by co-author Jennifer Botha of the GENUS Centre of Excellence in Palaeosciences and the University of the Witwatersrand were digging in South Africa’s fossil-rich Karoo Basin when they unearthed two giant nine to 13-foot-long saber-toothed predators in rocks that date back between 252 and 255 million years.

A retired field technician from Iziko South African Museum named Paul October works with the Inostrancevia fossils in the field.
Paul October, a now retired field technician from Iziko South African Museum, with Inostrancevia fossils in the field. CREDIT: Jennifer Botha.

After reviewing the geographic ranges and ages of the other top predators called the rubidgeine gorgonopsians that were normally found in the area, the team found that these local carnivores went extinct early in the Great Dying. By the time other animals began to go extinct, these apex predators were already gone.

“We did not have a good understanding of when these large predators appeared and went extinct in the African record,” study co-author and Field Museum research scientist Pia Viglietti told PopSci. “This was an important piece in the puzzle to answer because large-bodied predators tend to be at high levels of extinction risk. So, knowing when they went extinct is important for understanding the Great Dying.”

[Related: With bulging eyes and a killer smile, this sabertooth was an absolute nightmare.]

According to the team, these findings demonstrate that fossil-rich locations in South Africa are crucial to better understanding the most catastrophic event in Earth’s history. The team plans to look for more gorgonopsians from more northern parts of Africa and in Europe and to search for earlier records of Northern Hemisphere gorgonopsians moving into the southern part of Pangea.

This peek into the past also bears a warning for our future, since the team says The Great Dying is the historical event that most closely parallels Earth’s current environmental crisis.

“Both involve global warming related to the release of greenhouse gasses, driven by volcanoes in the Permian and human actions currently,” said Kammerer. “[They] represent a very rare case of rapid shifts between icehouse and hothouse Earth. So, the turmoil we observe in late Permian ecosystems, with whole sections of the food web being lost, represents a preview for our world if we don’t change things fast.”